D L O R NDistributed Learning Object Repository Network

Stephen Downes

April 29, 2003

open-education.org

What is DLORN?

• A system that allows content producers to distribute their learning resources

• A mechanism that enables the subject specific aggregation of learning resources from many sources

• A means to allow course authors to locate and use resources from many sources

DLORN, the Concept

• DLORN should be thought of as a concept, not a product

• The central idea is that learning resources are distributed through a network

• DLORN isn’t about content management, it is about content distribution

• The principles behind DLORN are those of the web: distributed, decentralized, open

DLORN: Basic Structure

Current Implementation

http://www.downes.ca/cgi-bin/dlorn/dlorn.cgi

Syndication Formats

• DLORN currently supports all versions of RSS with Syndication, Admin, DC and CC modules

• DLORN also supports all LOM fields as RSS modules (needs documentation)

• Planned: support for OAI repository harvesting

LOM Metadata in RSS

• Treat LOM as just another RSS Mod

• Prefix with LOM

• Example:<item rdf:about="http://careo.ucalgary.ca">  <title>Writer's Online Outline</title>   <link>http://www.2learn.ca/…/senoutline.html</link>   <lom:educational>

<lom:learningresourcetype>x</lom:learningresourcetype><lom:typicalagerange>xxx</lom:typicalagerange>

</lom:educational>   <dc:creator>kdh</dc:creator>   <dc:date>2003-04-16T15:52:24-07:00</dc:date>   </item>

LOM Metadata: Issues

• As usual, what does the ‘link’ tag point to?– Preferred: to the LO directly– Optional: to the LO metadata– Really not desired: to an HTML summary

page describing the LO

• Excess ‘junk’ in LOM– The endless ‘languagestring’ tags– The reference to VCard data

Metadata Repositories

• Intent is to conform to IMS DRI as much as possible – analogous to IMS ‘search intermediary’

• Expectation that there will be many metadata repositories

• MDs harvest metadata and provide search services to e-learning applications

MD Issues

• Some repositories do not make all metadata available – eg CAREO, most recent 10 items

• Some repositories don’t make any metadata available – eg. Corbis, Merlot

• MDs will have to output in a variety of (as yet unspecified) formats, eg., SOAP, XML-RPC, RSS, etc.

E-Learning Applications

• Right now, only the web browser, but of course MD output should be fed directly into applications, including:– Content aggregation tools– Learning Object browsers (akin to headline

viewers)– LCMSs and LMSs

Third Party Metadata

• Not yet supported

• Third party reviews of learning objects

• Aggregated by MDs and made available as part of search process

• Includes:– Categorization– Reviews– Certifications

Digital Rights

• DLORN will support the eduSource DRM component

• The reason is to place free and priced learning resources side by side in search results (if desired by searcher). Why?– Creates market for free materials– Undermines existing publisher monopoly– Results in realistic content pricing

DLORN: Complete Structure